[RFD] divecomputer time/date synchronization while downloading dives

[Linus Torvalds]

On Wed, Jul 19, 2017 at 9:12 PM, Miika Turkia <miika.turkia at gmail.com> wrote:
>
> Do we get the current time from the DC. If so, we could automatically
> adjusting the time of the downloaded dives.

I really do *not* want to do that. Why? You may be downloading after
your trip, because you were busy, and it's quite possible that your
dive computer was in the right time, an dyou're now "correcting" for
having moved back to your home time zone, and you go "oops, the dive
computer is set for Hawaii time, but I'm obviously in Portland, so all
those dives we downloaded obviously are wrong and have to be fixed
up".

That's obviously horribly horribly wrong.

So no. Correcting things after the fact is something you'd do manually
when you notice that you forgot to change the clock on the dive
computer, and then you go and actually edit the dives. But it's *not*
something you'd do based on your laptop time vs dive computer time.

>  have had one DC on incorrect time more than once at the
> start of dive trip. Wristwatch type DC is always set to local time but
> the bulky ones that are in hand luggage might get forgotten :(

Right, it happens to me too. I don't think we can fix that, and we
already have ways to just edit the dives after the fact when we
notice.

So what I want to do, and what I think we *can* do is to make it much
easier to just set the time. Usually time and date setting is just
pretty damn painful to do manually. So doing it from subsurface is
just much easier. You still have to remember to set the time, but at
least it's *easy* to do and get it set right to the second.

Particularly with the BLE dive computers and a cellphone, you can even
do it on the boat on the way to the dive site. Just initiate an empty
download (or another explicit action: the problem really is that we
currently don't even have the interface to libdivecomputer to do this
at all, so right now my EON Steel patch just always does it at dive
computer "open" time).

            Linus